A team led by Mary Scourboutakos, a postdoctoral researcher, decided to attack probiotic research. They searched a national database of product labels in Canada and analyzed 29 clinical trials conducted on the the health benefits of eating probiotics. What they turned up may surprise you. As it turns out, the hype isn’t all it seems-here’s what they found:

1) They’re Not Just Good For Your Gut

Studies have been done proving the benefits of probiotics go further than your gut. In the right amounts, they can also push out harmful bacteria in your body, work to prevent the common cold, help ease your symptoms if you have irritable bowl syndrome, and reduce your chances of getting a cavity. Winning all around.

2) There Are Different Kinds and No One Agrees Which is Best

That being said, the studies aren’t complete. No doubt, probiotics are good things, but exactly which strain does what isn’t yet known.

Kefir, for example, is touted as being jam packed with goodness. It often has the highest amount of probiotics in it, and the most variety but the mixtures in it haven’t been studied, and so their benefits aren’t truly known.

3) You Need to Eat More Than the Recommended Serving Size

Here’s the catch: researchers found that studies held up to their claims, but that sometimes you need to eat many times the serving size, to reap the benefits of the probiotics in the food.

This chart compiled by the researchers shows that when it comes to some yogurt products, you actually need to eat or drink between 8 to 25 servings a day for it to have any positive effect for your health. So, take a good look and buyer beware.

4) Most Studies Are Funded by Those Who Make Probiotics

The researchers found that most of the studies in their analysis were funded by the very makers of the probiotics being studied.

This is, of course, common practice in research that ties in with consumer products, but is it good? It should probably make consumers wary of the possibility of a conflict of interest.

What’s the bottom line? Yes, probiotics are beneficial. But your yogurt might not have enough in a single serving to do you well. If you really want to improve your health, do some research, eat sugar free yogurt (all that extra sweetness isn’t good for your gut), and consider taking probiotic pills to get the right amount.